Call for urgent action on Antarctic pollution

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A cocktail of heavy metals and petroleum hydrocarbons is polluting Antarctica and urgent action is needed, say Australian scientists.

In a study of the now abandoned Wilkes and Old Casey stations, Colleen Cole and colleagues from the Antarctic Division, found chemical contaminants are leaching from rubbish dumped in old tip sites, machinery parts and fuel drums during the summer melt.

The findings were presented at an international symposium on development in cold regions in Hobart today.

Contaminants, such as copper, lead, zinc and cadmium, are flowing into the marine environment and could be a significant threat to local wildlife.

"The common perception is that buried station waste and chemical spills in Antarctica are frozen and immobile, and that release and transport rates are therefore negligible", the scientists say. "The sites we studied around Casey and Wilkes Stations indicate that this is not the case."

The researchers collected samples of sediments, and surface and ground waters from sites known to be contaminated. They found that concentrations of metals were "greatly above environmental guideline levels."

An Antarctic Treaty, adopted in 1998, legally requires all countries based on the icy continent to protect and preserve its unique environment. Under the agreement, nearly all waste must now be removed from the Antarctic.

A chequered past

According to Martin Riddle and colleagues, also from the Australian Antarctic Division, humans have had a chequered history on the continent. In the past it was common practice to dispose of station waste as land-fill. Rubbish was pushed into the sea-ice and dispersed when the ice broke up during Summer.

The Wilkes and Old Casey stations were in operation between 1959-1969 and 1969-1989, respectively. Today, their impact on the surrounding environment remains obvious - and a major focus of Antarctic scientists is on the remediation and rehabilitation of these old bases.

According to the researchers, scientists still have very little understanding of how contaminants behave in the chilly Antarctic environment, and their impact on native flora and fauna. Studies of the soils can be especially difficult, hampered by the seasonal cycle of freezing and thawing.

The researchers also tracked the pathways by which heavy metals disperse into the marine environment. Their major finding indicated that contaminants are carried along by particles into water during the summer thaw.

In their presentation to the Sixth International Symposium on Cold Region Development, they recommended that procedures are developed to filter particles from water during the clean-up and remediation of Antarctic sites.